1. Field of the Invention
The present invention relates to a reproducing apparatus, and more particularly, to an apparatus for reproducing digital data from different types of recording media.
2. Description of the Related Art
There is conventionally known an apparatus for reproducing digital data from different types of recording media, such as a digital VCR for recording data on magnetic tape by compressing the amount of the information of a digital video signal.
In such a digital VCR, high-density recording is demanded due to the large amount of recording-information. The head and tape of the VCR are suitably designed for such high-density recording.
Many media having magnetic anisotropy in the longitudinal direction, such as a metal-particle tape (hereinafter called MP tape), have been used in a digital VCR. Due to demagnetization in recording, there is a limit to increasing the density of the MP tape.
In contrast, a metal-evaporated tape (hereinafter called ME tape) has a small amount of demagnetization since it has magnetic anisotropy at a constant angle perpendicularly, providing superior high-density recording. In terms of reliability and costs, however, the MP tape is superior.
As described above, since these two types of tape have advantages and disadvantages respectively, it is best to use them based on the anticipated recording density.
In addition to the above-described features of the MP tape and the ME tape, they have different waveform responses in reproduction according to the differences in magnetic anisotropy. FIGS. 1A and 1B show the respective reproduction waveform response.
As shown in FIG. 1A, the MP tape generates a single-peak, symmetrical waveform, and as shown in FIG. 1B the ME tape produces a dipulse waveform including an undershoot at the trailing edge in the reproduction waveform.
In the above-described digital VCR, waveform equalizing processing is applied to a reproduction signal to detect the reproduction data. The equalization characteristics used in the equalizing processing are designed according to the reproduction waveform.
Since the waveform of the reproduction signal in the MP tape differs from that of a reproduction signal in the ME tape, an equalizer circuit having single equalization characteristics cannot appropriately equalize signals reproduced from both types of tape.
Therefore, the type of tape which can be used is automatically determined in the above-described digital VCR. Different types of tape cannot be used according to different recording densities, restricting flexibility.